1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus of transmitting a scheduling request to request uplink resources in a wireless communication system
2. Related Art
3rd generation partnership project (3GPP) long term evolution (LTE) is an improved version of a universal mobile telecommunication system (UMTS) and is introduced as the 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink, and uses single carrier-frequency division multiple access (SC-FDMA) in an uplink. The 3GPP LTE employs multiple input multiple output (MIMO) having up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-advanced (LTE-A) that is an evolution of the 3GPP LTE.
A scheduling request (SR) is a control signal transmitted by a user equipment to a base station to request allocation of an uplink resource. Delay of SR transmission implies delay of the uplink resource allocation, which may cause deterioration in service quality.
Recently, with the introduction of multiple carriers, one user equipment can receive a service from a plurality of serving cells. With the introduction of the plurality of serving cells, there is a need for a method capable of more effectively scheduling SR transmission.